The present invention broadly relates to a new and improved device for preheating liquids, especially for preheating liquid fuels used for combustion and for powering engines.
Generally speaking, the device of the present invention pertains to a new and improved construction of a preheater or preheating device having a thermal-insulating or heat-insulating outer casing or jacket and, as a heat source, a superficial or surface heating element provided on the inner surface thereof.
In the preheater or preheating device of this general kind known from the German Patent No. 3,514,053 corresponding to the aforementioned copending U.S. application Ser. No. 06/851,112, the preheating device forms a superficial or surface heating chamber or space for the passage or through-flow of the liquid to be preheated. This heating chamber or space serves as a heat exchanger. The boundary surfaces of this heat exchanger are formed of heat-conducting metal walls. A superficial or surface heating element in the shape of a heating foil or a heating mat butts or rests directly against the outer wall of the heating chamber. This superficial heating element in turn is insulated and protected towards the outside by an insulating wall, a metal casing or housing, and an additional outer insulation or insulating covering. This preheater or preheating device advantageously comprises a bowl or pot-shaped casing or jacket. Upon this bowl or pot-shaped casing or jacket there is threadably attached a cover possessing the connecting channels for the heating chamber. If the cylindrical inner wall of the heating chamber of this bowl or pot-shaped casing or jacket comprises a sufficiently large hollow space or cavity, then a filter for liquids can be installed in the inner portion of this bowl or pot-shaped casing or jacket such that the preheater or preheating device and the filter for liquids form a structural unit.